Semiconductor memory is widely used in various electronic devices such as mobile phones, digital cameras, personal digital assistants, solid-state drives, medical electronics, mobile computing devices, and non-mobile computing devices. Semiconductor memory may comprise non-volatile memory or volatile memory. A non-volatile memory allows information to be stored and retained even when the non-volatile memory is not connected to a source of power (e.g., a battery). Examples of non-volatile memory include flash memory (e.g., NAND-type and NOR-type flash memory) and Electrically Erasable Programmable Read-Only Memory (EEPROM), including re-writable non-volatile memory cells, such as two-terminal resistive RAM (ReRAM) memories.
It is common for semiconductor memory die to be placed into a package to allow for easier handling and assembly, and to protect the die from damage. Although a plural form of “die” is “dice,” it is common industry practice to use “die” as a plural form as well as the singular form. In one example, semiconductor memory die and/or other integrated circuits, such as processors, may be encased within a package wherein the die may be stacked on top of one another within the package. The package may be a surface-mount package (e.g., a BGA package or TSOP package). One benefit of vertically stacking die within a package (e.g., stacking 16 die within a single package) is that form factor and/or package size may be reduced. In some cases, the package may be a stacked multi-chip package, a system-in-package (SiP), or a chip stack multichip module (MCM). Vertical connections between the stacked die including direct vertical connections through a die's substrate (e.g., through a silcon substrate) may be formed within each die before or after die-to-die bonding.